Oxygen administration system



P 1951 A. E. MGKEE ETAL 2,567,224

OXYGEN ADMINISTRATION SYSTEM 3 Sheets-Sheet 1 Filed Aug. 17, 1943 P 1951'A. E. MCKEE ETAL 2,567,224

OXYGEN ADMINISTRATION SYSTEM 3 Sheets-Sheet 2 Filed Aug. 1'7, 1945INVENTORS,

p 1951 A. E. M KEE ETAL 2,567,224

OXYGEN ADMINISTRATION SYSTEM Filed Aug. 17, 1943 3 Sheets-Sheet I5Jig-J.

e5 PYZI/e W5 63 @556 7 75' E/VaJ Z Jizme Z4 21550770 Patented Sept. 11,1951 OXYGEN ADMINISTRATION SYSTEM Albert E. McKee, Chicago, and James D.Elsom, Evanston, 111.; said Elsom assignmto said McKee ApplicationAugust 17, 1943, Serial No. 498,973

14 Claims. (Cl. 128-442) Our invention relates to oxygen administeringsystems and apparatus for use therewith.

Oxygen is administered under a variety of conditions to secure varioustypes of results and in various ways, depending upon the conditionsfound and the results desired. The copending application of AlbertE.McKee, Serial No. 537,803, filed May 29, 1944, discloses improved oxygenadministering equipment and in certain respects, at least, our presentinvention is an improvement over the invention disclosed in the saidcopending McKee application. The McKee invention was adapted for use byaircraft personnel, at high altitudes, but had other uses and the systemand apparatus of our invention, while still having at least the utilityof the McKee apparatus, has added features and advantages, particularlyso far as aircraft personnel and the like are concerned.

There are very definite disadvantages which have been found to exist inoxygen equipment, one of the principal of which is that no equipmentwith which we are familiar has been sufficiently versatile in the usesto which it can be put to satisfy usual demands caused by varyingconditions. For a given purpose even, much of the equipment used hasproven unsatisfactory. In order that those skilled in the art mayunderstand more fully the features and objects of our invention, we wishto point out briefly the nature of some of the problems involved.

Generally speaking, it is undesirable to deliver oxygen to aircraftpersonnel below about 10,000 feet. From 10,000 to approximately 38,000feet, a mixture of oxygen and air or pure oxygen may be deliveredsubstantially at ambient pressure. Above approximately 38,000 feet, itis necessary to supply 100% pure oxygen at some positive pressure oninspiration to avoid anoxia. Generally speaking, it is desirable, if notnecessary, that an oxygen administering system include provisions fordelivering ordinary air to the aircraft personnel at lower levels withthe oxygen mask in position on the face. Oxygen or a mixture of air andoxygen at the inspirational demand of the subject at ambient pressure orsubstantially at ambient pressure (mere flow of oxygen bearingatmosphere) and at a controlled positive pressure above ambientpressure, also on inspirational demand of the subject, since thetransporting of oxygen to and on the airplane is a matter ofconsiderable expense, economy of administration and utilization ofoxygen is essential. Any system which makes use of continuous flow ofoxygen is, therefore, un-

. a 2 I desirable. Demand regulators which require negative pressurethroughout the inspirational cycle have certain disadvantages and anypressure system which requires expiration against a positive pressure isalso undesirable.

Under certain conditions, even in aircraft (such as if the subjectshould become unconscious and incapable of exercising positiveinspiration function), it may be necessary to operate oxygenadministering equipment in accordance with a rhythmic cycleautomatically and without the necessity of the subject making any demandas by inspiration. It is also desirable to avoid, so far as possible,any substantial rebreathing such as might lead to the freezing ofcontrol or regulating equipment and there are certain very definiteadvantages in the provision of a separate expiratory valve so that thereis no occasion to exhale through the-entire mechanism. Some rebreathingor provisiion'of other means for assuring the, presence; of adequateproportions of carbondioxide-tostabllize inspiration at a normal rateis, of course, desirable.

The object of ourinvention is the provision of an improved oxygenadministration system, particularly one which secures the advantages andovercomes the problems identified hereinabove. Another object istheprovision 'of oxygen administration apparatus; adapted for use undera variety of conditions and-for" avariety of purposes but havingparticular utility in meeting the many demands of oxygen apparatus foraircraft personnel at medium and very high altitudes.

In accordance with our invention, oxygen is delivered to the subject onhis demand ,on inspiration but with a positive flow after the firstslight inspiratory effort. Thus the subject is notrequired to inhaleagainst a negative pressure during the entire inspiratory cycle.Operated at intermediate altitudes at which a mixture of oxygen and airor pure oxygen is breathed and can be utilized by the subject readily atambient pressure, there is a mere flow of oxygen on demand with onlysufiicient pressure to cause a continued flow. Means is provided,however,

for increasing the pressure so that the equipment operates on demandwith a positive pressure. Whether operating at the demand of the subjectat substantially ambient pressures or above, the cycle reverses at apeak pressure in slightly, sayone-half inch, above ambient pressure, toa predetermined value, say eight inches, or more above ambient pressure,depending upon design. The control of this pressure is mechanical andmay be made by the subject at any time and the attainment of the peakpressure at which the cycle reverses is subject very greatly to theattitude of the subject so that a substantially normal breathing cyclemay be maintained and the apparatus may be automatically compensated toa considerable extent for the oxygen demands of different subjects.Means may be provided, however, for adjusting the supply to the demandsof a particular subject.

The apparatus is also operable on an automatic principle without demandof the subject, that is to say, without the necessity of the developmentof a negative pressure in the administration line caused by inspiratoryaction of the subject. Breathing under this adjustment may be maderhythmic and automatic, pressure in the line havpendently of demand, atany pressure within the limits of the design, we also provide additionalfeatures of a novel and valuable character. We provide valve means forcontrolling the flow of oxygen from a pressure source to theadministration line which may be adjusted to operate at only a fractionof an inch of pressure so that very little effort is required oninspiration to cause a flow of oxygen to the subject. This valve meansincludes a toggle switch operated by a diaphragm, operating a relativelysmall valve which operates in the nature of a relay to provide pressureand operating a larger valve through which flow of oxygen is actuallycontrolled. We also provide a separate expiratory valve which'may bemounted directly in the line and fastened, for example, to the clothingof the subject so that it may readily be maintained at a suflicientlyhigh temperature so that freezing is avoided. The expiratory valve isprovided with means for adjusting the expiratory orifice so that therate of discharge through the expiratory valve, and, therefore, the meanpressure, through the expiratory cycle, may be controlled. The apparatusis so constructed and arranged that the principal portion of theapparatus adapted for direct attachment to a source of oxygen may bemaintained at a convenient place in an airplane or the like andconnected to the separate expiratory valve by suitable flexible tubing.Any type of close fitting closed mask, including any mask especiallyfitted to a particular subject, may then be used and readily connectedbetween the flexible tubing attached to the mask and the expiratoryvalve.

Other objects and features of the invention may be apparent from aconsideration of the following detailed description taken with theaccompanying drawings showing one embodiment of the invention.

In such drawings- Fig. 1 is an elevational view of control apparatusother than the expiratory valve, mask and flexible tubing, adapted forattachment to a suitable mounting bracket or the like, which controlapparatus, for convenience, is referred to hereinafter as the regulator;

Fig. 2 is a plan view of the regulator shown in Fig. 1;

Fig. 3 is a composite view showing the regulator in section (taken alongthe line 33 of Fig. 2), the expiratory valve in section, the maskschematically in its proper position, and with connecting tubing brokenaway, the parts being connected together in the manner in which they areused during operation;

Fig. 4 is a transverse sectional view of the ex piratory valve taken onthe line 4-4 of Fig. 3;

Fig. 5 is a fragmentary sectional view taken on th line 5-5 of Fig. 3looking in the direction of the arrows; and

Fig. 6 is a sectional view similar to the section of the regulator shownin Fig. 3 but showing the valves in open position.

As utilized, the embodiment of our invention shown in the drawings,comprises a regulator indieated generally by the reference character A,

an expiratory valve indicated generally by the reference character B,and a suitable close fitting closed mask indicated by the referencecharacter C. The mask is connected to the regulator by flexible tubingof suitable cross section comprising an oxygen administration line andthe expiratory valve is set in this line at a suitable point so that theexhaled breath passes through the oxygen administration line only as faras the expiratory valve, which, by its nature, is readily protectedagainst extremes of temperature, and there is never any moisture fromthe breath which will reach the regulator mechanism.

The regulator is relatively light in weight and suitably formed tocomprise, as shown, four main frame parts, H), H, I2 and I3, adapted tobe suitably secured together by machine screws or the like which havenot been shown in the drawings, the purpose being to avoid obscuringessential features of the apparatus. The frame part II) is provided witha suitable flange H for attachment to a mounting bracket or the like. Aboss I5 is provided on the frame part II for the attachment of a pipeconnected to a suitable source of oxygen, valve controlled in the usualway common to oxygen therapy and auxiliary oxygen administrationpractice. A suitable outlet l! is provided on the frame part ID forattachmrnt to flexible tubing comprising the oxygen administration line.

Referring now, also, to Figs. 3 and 6, a regulating diaphragm I8 issecured between the frame parts It! and II and a booster diaphragm l9between the frame parts l2 and 13. A passageway 2| leads from the oxygensupply source at the boss IE to a chamber 22 which, therefore, is at alltimes filled with oxygen under substantially the pressure of theincoming line and the passageway 2|. A vertical passageway 23 leads fromthe pressure chamber 22 to atmosphere, but this vertical passageway 23is adapted to be closed at either end by a double ended valve 24.Another relatively small passageway 26, shown in dotted lines, leads toa chamber 21 in the frame part l3 but having as one side thereof thediaphragm I9. Diaphragm I9 is connected with a double ended valve 28disposed in a larger vertical passageway 29 which passagewayinterconnects pressure chamber 22 and a chamber below the boosterdiaphragm 19 open to atmospheric pressure through a bleeder line 3|. Thevalve 28 is adapted to close either end of passageway 29 so as to placepressure chamber 22 in communication with an oxygen delivery passageway32 (in the position shown in Fig. 6), or to interrupt delivery of oxygento the delivery passageway 32 and open such delivery passageway 8 toatmosphere through the bleeder Ii. The delivery passageway 32communicates with a verconnected to the lower portion of diaphragm l8tical port 33 leading to a diaphragm chamber e by ahousing 88 threadedtoa'boss 6| on the frame 34 which is also in communication with theoutlet l1 and hence, in a manner to be described,

delivers oxygen to a subject. A small passageway 38 also communicateswith the passageway 32 and with'a relatively small line 31 in the natureof a tube, the purpose of which will be described later.

The flow of oxygen to the delivery passageway 32 'and thence to thedelivery line through the outlet i1 is controlled by the valves 23 and28 although a plunger 38, which will be described later, has a bearingupon the rate of flow. The valves 23 and 28 are adapted to seat atcontiguous portions of the frame members which comprise valve seats.While these valves may be permitted to remain loosely in position andwill be returned after actuation throughair pressure, it will beunderstood that actually positioning bearings are provided but not shownin the drawings because to do so would merely mask the essentialfeatures which it is the purpose of this specification to describe. Thevalve 23 is operated by a toggle or overthrow type switch mechanism, tobe described, to control the delivery of oxygen under pressure tochamber 21 and the valve 28 is operated by movement of the diaphragm l8due to oxygen pressure to the position shown in Fig. 6.

The toggle or over-center type of switch mechanism is shown in twopositions in Figs. 3 and 6 and also in elevation in Fig. 5. Thisincludes a supporting bracket 38 depending from frame part II to whichare pivoted a valve control arm 4i and one arm 42 of a compound levermechanism to the opposite end of which a second arm 43 of the levermechanism is pivoted. Arms 42 and 43 carry cross pins 44 and 45,respectively, to the extremes of which are attached ends of a pair oftension springs 41. The arms 42 and 43, at the point of pivot to eachother, are also pivoted to a switch actuating member 48. Valve controlarm 4i carries a pin or machine screw 48 which is placed between endbifurcations of the switch arm 43. The springs 41, arms 42 and 43, andswitch actuating member 48 together comprise an over-center type ofmechanism such that the springs 41 may snap to one side or the other ofthe pivot point between the arms 42 and 43. The bifurcation at the endof arm 43 may, therefore, either engage against the bottom of the valvecontrol arm 4| to push it upwardly and operate the valve 24 to'place thepressure chamber 22 in communication with the vertical passageway 23 orengage against the top portion of an adjustable nut carried on the pin48 and permit return of the valve 24 whereby to seal oil the chamber 22and open the chamber 21 to atmosphere. The uppermost position of theswitch mechanism is determined by the valve 24 and the lowermostposition is determined by a stop 52 which pin 48 is adapted to engage.

A switch actuating rod 58 is suitably carried by diaphragm i8, as shown,and has a head 54 disposed within the switch actuating member 48preferably so as to have some lost motion with respect thereto. Movementof the rod upwardly past the point where the fulcrum between the arms 42and 43 s in line with the point of support of the springs 41 causes thevalve 24 to be closed and shut oil the supply of oxygen.

The plunger 38 controls the flow of oxygen into the chamber 34, asalready referred to, and it also forms a link between a spring 58 and arod 51 and comprisingessentially' a continuation oi rod 53. Spring ishoused in a chamber 58, formed part i8, concentric with the port 33. Theupper end of'spring 56 is secured to the bottom of plunger 38 and thelower end is secured to a screw 62 threaded in the housing 58 inalignment with the plunger 38. The screw 82 has secured thereto,exteriorly of the housing 59, an arm 63 adapted to be thrown to eitherof two positions adjacent stops B4 and 68. An aperture Bl is provided toequalize the pressure at opposite ends of plunger 38. The upper portion38' of the plunger 38 is restricted and the nature and purpose of thisrestriction will be described later. In order to control the peakpressure at which oxygen demanded by the subject discontinues flowingand the expiratory valve, to be described later, is opened, we provide apeak pressure control spring 68 carried by a pressure control member 89trheaded in a portion of the frame part II. As shown particularly inFig. 5, the threads have a very long lead or the pitch is great such as,for example, two threads to the linear inch. The lower part of thespring is never in contact with the diaphragm at rest position, that isto say, in the position which the diaphragm has in Fig. 6, but isadapted to be engaged by the diaphragm as the diaphragm moves upwardlywhen the device is operated on the demand principle, to be described.The pressure control member has secured thereto a pressure control armll, leading out to a scale 12 calibrated in any suitable wanner such aspounds per square inch pressure, altitude, inches of pressure aboveambient pressure,

or the like. As the pressure control arm is moved from one position toanother, the lower portion of the spring is moved closer to or furtheraway from the top of the diaphragm. At its maximum position of removal,the diaphragm will not contact it and the supply of oxygen may bediscontinued in a manner to be described, without influence at all fromthe spring 88. If the spring 68 is in such position that the diaphragmwill engage it before the switch mechanism is actuated to shut off theflow of oxygen, then the pressure in the chamber 34 at which oxygenceases to be delivered is determined by the degree to which spring 88must be compressed before operating the switch mechanism.

The expiratory valve shown in two sections at right angles to each otherin Figs. 3 and 4, includes a housing 13 containing a diaphragm l4 and aplunger 18 urged by a spring ll in a direction to move a valve 18 awayfrom its seat 19. The plunger 16 is vertically reciprocable in guides 8|connected to the housing 13 and the top end of spring 11 engages againstone of these guides and the bottom against a stop 82 in the nature of aflange so that normally to urge the valve 18 away from its seat 18. Theextent to which the spring may urge the valve away from its seat isdetermined by the position of a bell crank lever 83, the position ofwhich may be adjusted by a screw 84. Thus the screw 84 may be employedto adjust the size of the expiratory orifice, thus determining theresistance to exhalation. Resistance to exhalation may be determined inpart, also, by fixed openings 88 in a cap provided on the expiratoryvalve. A fluttervalve 81 is provided between the valve seat 18 and theopenings 88, this valve being very light in weight and so arranged thaton exhalation it can readily be lifted from its seat but on inhalationit, as readily, is drawn to its seat so that on inspiratory demand ofthe subject a slight negative pressure may be created in the oxygendelivery line so as to operate a diaphragm and valve mechanism.

The expiratory valve is provided with suitable nipples 88 and 89 forreceiving flexible tubing 9| 1 and 92, the former extending to theregulator A and the latter to the face mask C. Within the flexibletubing 9| is a relaitvely small tube 93 connected to the small line 31,previously described, and to a tube 94 carried by the expiratory valveand connected to a diaphragm chamber 96 for actuation of the diaphragm.While the'tubes 8| and 92 may readily be disconnected from the equipmentwith which they normally connect the tube 9| will normally remainconnected to the expiratory valve and regulator and one end of tube 92will normally be left connected to the mask C which may be theindividual maskof the subject or user of the equipment. Preferably,also, the expiratory valve B is so arranged as to be carried on, near orin the clothing of a subject when the device is used in aircraft and thesubject will normally take his position in the aircraft, attach theexpiratory valve to his clothing by suitable means such as a clip (notshown), and, when there is a demand for oxygen, attach the tube 92 andset the equipment in operation.

As previously pointed out, the device is capable of operating in severaldifferent ways, depending upon requirements. We shall assume first thatthe springs 68 is moved to its uppermost position, that is to say, thatthe arm ll is set over to zero or ambient pressure. Assume, further,that spring 56 is adjusted to a position where it cannot, alone, returnthe switch mechanism to the position where valve 24 will close theopening to passageway 23. The operation can be understood from the factthat the parts in Fig. 6 are in the position which they assume when thesubject has just started inspiration and he has tripped the valvemechanism and oxygen has just started to flow into the deliverypassageway 32. It is to be understood, also, that the parts of theregulator in Fig. 3 are in the position which they occupy just beforeinitial inspiration.

It is to be understood, however, that the spring 68 is assumed in ourhypothetical case to be at its uppermost position so that pressure willnot build up in the chamber 34 to a point above or substantially aboveambient pressure.

Under the conditions pointed out, let us assume that an aviator it at25,000 or 30,000 feet and has his mask in position, he is breathing pureoxygen from a suitable pressure tank and through a connection leading toboss l6 and incoming passageway 2|. He has finished exhaling and theparts are in the position shown in Fig. 3 and now starts to inhale. Theflutter valve 81 has fluttered to its seat and his action in startin tobreathe causes a slight negative pressure in the delivery line andthereby a slight downward pull on diaphragm l8. This trips over theswitch mechanism and the parts are now in the position shown in Fig. 6.This occurs because of the movement of the valves and the action of thebooster diaphragm I9, previously referred to. Oxygen is delivered topassageway 32 under pressure, say of eight pounds per square inch, andthere is an immediate surge of oxygen into the chamber 34 to be madeimmediately available to the subject, this surge occurring because, dueto the fact that the port 33 is substantially entirely open except forthe rod 51, there is a maximum orifice to permit maximum movement of theoxygen into the chamber 34. As soon as this occurs, there is a slightupward movement of the diaphragm with the result that the restrictedportion 38' of the plunger occupies that portion of the port 33 throughwhich the oxygen must pass and thereafter there is a steady demandedflow of oxygen. As long as the subject continues to inhale, oxygencontinues to flow but as soon as he has discontinued inhalation, thereis a slight momentary rise of pressure in chamber 34 which thereby tripsthe switch mechanism, closes the valve 28 and discontinues the flow ofoxygen. As this cycle takes place, the expiratory valve also goesthrough a cycle due to the operation of the valve member 18. This occursin the foloxygen under pressure.

lowing manner: When the parts reach the position shown in Fig. 6 andoxygen commences to be delivered to the chamber 34, it is also deliveredunder pressure to the line 37, the opening to this line being sopositioned that a positive pressure is applied on the line 31 and iseffective to operate diaphragm 14 which engages the plunger 16 and movesvalve 18 against its seat. When the oxygen delivery flow to the deliverypassageway 32 is interrupted, this cycle is reversed, the passageway 32is open to atmosphere and the spring TI is permitted to open the valveas far as permitted by the setting of the screw 84. We have found thatthe pressure required to operate the switch mechanism may be at anabsolute minimum. In the operation of a device constructed in accordancewith the present invention, the effort on inspiration required to movethe diaphragm i8 downwardly sufficiently to trip the valve controlmechanism is so slight as hardly to be noticeable. It may readily becontrolled to be not more than inch of negative pressure. Similarly, thereturn movement of the diaphragm takes place with not more thanapproximately inch of positive pressure in the delivery line so that forall practical purposes there is merely a flow of oxygen at ambientpressures.

We postulated feeding of pure oxygen but it is to be understood that atintermediate pressures, say 10,000 to 15,000 feet, it is desirable attimes to make available a mixture of air and oxygen and this may be donewith the apparatus of our invention in several different ways which havenot here been described because they are not of importance in connectionwith the present invention. The mixing device may be incorporated aspart of the regulator or may be outside of the regulator, depending uponseveral factors which need not be discussed here. We merely wish topoint out that the apparatus of the present invention is not limited tothe administration of pure oxygen. Those skilled in the art willunderstand also that the mask C may be applied in position at loweraltitudes and an airman may continue to perform his duties with the maskin position, the tube 92 being disconnected from the expiratory valveand the airman merely breathing ordinary atmosphere at low altitudepressure. This may be necessary or desirable because of the utilizationof masks with microphone or other equipment and it is obvious that thesystem of our invention adapts itself to any of these needs. It is notnecessary to employ separate masks or separate devices but the same maskmay be employed throughout a flight.

Let us assume now that it is desirable to operate the equipment in sucha way as to deliver An aircraft may be required "to-operate above 38,000feet; for example, setting of the expiratory valve. When the presatwhichjelevationeven-pure oxygen at ambient sure in the line has droppeddown to the point pressure will not 'preventanoxia'. The subject wherethe diaphragm and valve mechanism may nowgrasps the control arm 11' andmoves it to be returned to lowermost position, assisted by the proper"position along the scale 12. If" the'scale spring 56, the valvemechanism is again tripped, is calibrated in altitude he may. forexample. oxygen delivered to the delivery passageway 32 move it to38,000 feet (or meters) or itmay be and the cycle again initiated.Probably the creaseslightlyin the chamber 34' the-case when the devicefunctio M thesubject is free to exhale normally; He can calibrated insome other value-but, in any event, utility of the automatic feature ofour invention it represents an increase in oxygen pressure in will begreatest when used in other locations than the delivery line at a figureabove ambient presin aircraft such as in the treatment of pulmonarysure. 'By this operation, he urges-the spring 68 edema caused by poisongas or the like. Appardownwardlyso that before the diaphragm l8 ently,however the inclusion of this feature in can be moved upwardlyaQsufiicient-distance to apparatus intended for aircraft work may be oftrip the valve control mechanism, the spring 68 great advantage;particularly in the saving of must be partially compressed. -,The extentto j life of any ,crew. member taken seriously ill or which the spring68 mus'tibe compressed deterwounded at high altitudes.

mines the pressure above a'mbient pr' which j .Mostof thefeatures of ourpresent invention must be-Ide'veloped in. the chamber "e apparent tothose skilled in the art from tripping .or the valve mechanism T] viption. We wish to point out. now operates in exactly the same however,.thatyin addition. to the adjustments scribed vhereinabove withtheiexceptio jwhichmay madein m chani onstructed in gen is positivelyfor ed t f pm accordance with the present invention, the usual ubje tinstead f merely -a adjustments and controls common to the art of sponseto his'action in inhaling. when heis'ub' y n therapy or Oxygenadministration can jectfs', have i been fin also be' used. We pointedout that oxygen might he resists furtherlmhamtiony 5- w be de'liveredtothe regulator at approximately ight pounds of pressure; Any usual meansfor .rnaintaining this pressure can be employed. It an ambient pressuredemandqr g fm rb f n rh v that a s ma11 subject cycle is reversed, theexpiratory?- "alve 'pejnl and- M 3' P u d Pressure recelve somewhat momuchoxygen when the device is operated on the demand principle atambient pressures. Should this be found to be the case, it is onlynecessary control the peak pressure against which he ex-j hales byadjusting the expiratory orifice. When,

now, hehas exhaled and the pressure has been released in the deliveryline and in the chamber 34, the mechanism remains at rest and there isno flow of oxygen until further inspiratory demand by the subject. Thediaphragm will have dropped to a lowerposition so that it entirelyclears the spring 68 and the spring is no longer a factor intheoperation of the device. He now to five or six pounds per square inch,by valve tomarily furnished with oxygen containers and regulators. Thedevice of the present invention may be made relatively small and lightfor use 0 in an airplane with the separate expiratory valve in themanner suggested or it may be embodied makes asnght inspiration,a'slight negative pres in other forms adapted for an entirely differenttype of use. The expiratory valve may, for exre develo a the c 1 re eitsel z g zfi g g e v p ats f m ample, be included in the same housingas the If, for any reason, it is desirable to operate regulator or maybe lled directly in the the system of our invention without requiring Ina t g i g? of 2 g g gi va ve may e re aine incu mg e a y a positivedemand on the part of the sub ect control the mean pressure and imam amgh to cut the incoming pressure down slightly, say

means always provided with equipment cus-' before the tripping of thevalve mechamsm and mean pressure over a relatively long period thedelivery of oxygen to the delivery line, this is accomplished readily byadjusting the screw zgfig zi g ggggg 2 32x 2 the pres- :2 Ti: strait:2m: matin e we w position of the plunger 38, and the fact that on addthe equivalent of one inch to the tension first. demand there may be asurge of Oxygen so fiiflififiiiitei'iifii. strate ies? as to immediateof nism with the assistance of diaphragm action It should be noticedthat if the subject should at due to negative pressure in the chamber34. The g g 223 123; g g g ggg xg g ffiggfi; g i z occurs automatlcany'The oxygen 15 there will be another surge of oxygen because Qwere atwhaitever pressure may be deter the diaphragm will be drawn downslightly. This mmefi by the P the control j and is merely illustrativeof the many ways in which to flow m the predetermmed peak the device ofour invention will meet the needs Pressure 15 reached t thls of asubject under varying conditions. Further Point the Valve tnpped andexemplification of the functioning of the system delivery of oxygen 15dlscontmueq- The 6 of the present invention may be had from a contoryvalve also opens and the subJect can exhale. sideration of the copendingapplication of m In th v nt th su i t s l consciousness, E. McKee,Serial No. 530,968, filed April 14, 1944. o e o as c a With h m creadily adjust Reference should be made particularl to the ex- 1105mm!0f the m 63 and the apparatus planatory curves and explanation thereofform- WIlu-then operate ona resuscitator principle. The ing a part ofsuch copending application subjects lungswillbe filled with oxygen undert has been suggested t anerojds be pressure, when the peak pressure isattained the played to control certain adjustments on oxygen e pirat ryValve Will eop n andmllscle tOnuS regulators, and it is understood thatmost, if is adequate to cause expiration. The rate of not all, of thecontrols referred to hereinabove as expiration is, of course, controlledagain by the being employed as part of, or in conjunction with,

our invention, may be operated, if desired, by suitable aneroidmechanism.

Our invention may take various forms and the scope thereof is defined bythe claims.

What we claim as new and desire to protect by Letters Patent of theUnited States is:

1. In a valve mechanism for an oxygen administration system, an outletside thereof, valve means controlling flow 01' oxygen from a sourceunder pressure to said outlet side, a diaphragm for controlling saidvalve means, said diaphragm operable on demand for oxygen to cause aflow thereof substantially at ambient pressure through said valve meansand discontinuance of flow when inhalation ceases, manually controlledmeans for loading said diaphragm whereby to cause the oxygen flow todiscontinue only when a peak pressure is attained above ambientpressure, said valve means including an over center switch responsive tothe position of said diaphragm, said switch operating a valve foradmitting oxygen to a chamber adJacent said diaphragm, and means topermit more rapid flow to said diaphragm chamber when said valve isfirst opened than during remaining portions of the inspiration cycle.

2. In a regulator of the class described, an oxygen delivery line, avalve operable to control the delivery of oxygen from a pressure sourceto said line, a booster diaphragm operable to control the position ofsaid valve. a diaphragm mechanism responsive to pressure in the saiddelivery line, valve mechanism responsive to operation of the saiddiaphragm mechanism, said valve mechanism controlling flow of highpressure oxygen from said pressure source to said booster diaphragm,whereby to operate the same and actuate the first mentioned valve, andmeans to control'both the high and low pressure points in said line atwhich said diaphragm mechanism operates, said last mentioned means beingcontrollable to require either a positive or negative pressure in thesaid line to initiate oxygen fiow after it has been interrupted.

3. In an oxygen feeding system, a mask, a valve device having a housingwith one chamher in communication with the mask and one chambercommunicating with atmosphere, a pressure responsive device between thetwo chambersnan expiratory valve having an orifice communicating withsaid mask, a pressure responsive device controlling said expiratoryvalve to close the same, said valve being biased for opening movementthereof, a line supplying oxygen under pressure, a valve in said linecontrolling fiow of oxygen to said mask and said pressure responsivedevice for said expiratory valve, over center switch means operated bythe first-mentioned pressure responsive device when the pressure in themask reaches a predetermined peak pressure, to interrupt oxygen flow tosaid chamber and mask, and adjustable spring means biasing said ressureresponsive means toward said first-mentioned chamber, said means beingjust insufiicient to operate said oxygen valve means and deliver oxygenwhen the pressure therein ap proaches atmospheric pressure, butresponding to move said pressure responsive means and operate said valvewhen a slight negative pressure is established, and means foradditionally loading said pressure responsive device to cause returnmovement and operation of said valve to admit oxygen when the pressurein the mask is lowered substantially to atmospheric.

4. In an oxygen administration system, a regulator including a casingforming a low pressure oxygen chamber and a high pressure oxy chamber, adiaphragm having one side in contact with said low pressure chamber, anovercenter switch operated by movement of said diaphragm, a controlvalve operated by said switch, a second diaphragm having a chamber onone side thereof, a main valve operated by said second diaphragm, apassageway leading from said high pressure chamber to said diaphragmchamber, said passageway being opened by said control valve, a secondpassagewa between said high pressure chamber and low pressure chambercontrolled by the said main valve, the relationship of the parts beingsuch that movement of the first mentioned diaphragm in response to aminimum and maximum pressure will close or open said control valve andthe second mentioned diaphragm will thereby close or open the said mainagainst said spring pressure, and a passageway leading from said mainvalve passageway to said pressure responsive mechanism when the oxygenis flowing from the said high pressure chamber to the said low pressurechamber.

5. In an oxygen administration system, a regulator including a casingforming a low pressure oxygen chamber and a high pressure oxygenchamber, a diaphragm having one side in contact with said low pressurechamber, an overcenter switch operated by movement of said diaphragm, acontrol valve operated by said switch, a second diaphragm having achamber on one side thereof, a main valve operated by said seconddiaphragm, a passageway leading from said high pressure chamber to saiddiaphragm chamber, said passageway being opened b said control valve, asecond passageway between said high pressure chamber and low pressurechamber controlled by the said main valve, the relationship of the partsbeing such that movement of the first mentioned diaphragm in response toa minimum and maximum pressure will close or open said control valve andthe second mentioned diaphragm will thereby close or open the said mainvalve to cut off the flow of oxygen, or deliver oxygen to said lowpressure chamber, an expiratory valve normally biased in one direction,pressure responsive mechanism for moving said valve against said normalbias, and means for delivering oxygen from said high pressure chamber tosaid pressure responsive mechanism, when said main valve is opened todeliver oxygen to said low pressure chamber.

6. In an oxygen administration system, a regulator including a casingforming a low pressure oxygen chamber and a high pressure oxygenchamber, a diaphragm having one side in contact with said low pressurechamber, an overcenter switch operated by movement of said diaphragm, acontrol valve operated by said switch,

13 and maximum pressure will close or open said control valve and thesecond mentioned diaphragm will thereby close or open the said mainvalve to cut off the flow of oxygen, or deliver oxyline, a boostermechanism operable to control the position of said valve, mechanismresponsive to pressure in the said delivery .line, valve mechanismresponsive to operation of the said pressure responsive mechanism,saidvalve mechoxygen from a pressure source to said outlet anismcontrolling flow of high pressure oxygen from said pressure source tosaid booster mechanism, whereby to operate the same and actuate thefirst mentioned valve, and means to control both the high and lowpressure points in said line at which said pressure responsive mechanismoperates, said last mentioned means being controllable to require eithera positive or negative pressure in the said line to initiate oxygen flowafter it has been interrupted. 3

8. In a valve device for an oxygen feeding system of the characterdescribed, an outlet side thereof, a valve operable to control deliveryof oxygen from a pressure source to said outlet side, a diaphragmmechanism responsive to pressure at said outlet side, mechanismincluding a booster diaphragm actuated by oxygen delivered directly fromsaid pressure source responsive to operation of said diaphragm mechanismto control movement of said first mentioned valve, means for actuatingsaid diaphragm mechanism and opening said first-mentioned valve onestablishment of a negative pressure at said outlet side, and means formoving said diaphragm mechanism in a reverse direction to close saidvalve when a predetermined peak positive pressure is attained at saidoutlet side, whereby to discontinue flow of oxygen to said boosterdiaphragm, the said mechanism functioning at slight pressuredifferential at said outlet side. I

9. In a valve device for an oxygen feeding system of the characterdescribed, an outlet side thereof, a valve operable to controLdeliveryof oxygen from a pressure source to said outlet side, a diaphragmmechanism responsive to pressure at said outlet side, means forcontrolling the load on said diaphragm mechanism whereby to control thepressure at said outlet side to which said mechanism is responsive,mechanism including a booster diaphragm actuated by oxygen delivereddirectly from said pressure source responsive to operation of saiddiaphragm mechanism to control movement of said first mentioned valve,means for actuating said diaphragm mechanism and opening saidfirst-mentioned valve on establishment of a negative pressure at saidoutlet side, and means for moving said diaphragm mechanism in a reversedirection to close said valve when a predetermined peak positivepressure is attained at said outlet side, whereby to discontinue flow ofoxygen to said booster diaphragm, the said mechanism functioning atslight pressure differential at said outlet side, re-

gardless of the peak pressure at said outlet side.

14 thereof, a valve operable to control delivery of oxygen from apressure source to said outlet side, a diaphragm mechanism responsive,to pressure at said outlet side, mechanism responsive to operation ofsaid diaphragm mechanism but powered by oxygen pressure from saidpressure source, for controlling the movement of said first mentionedvalve, means for actuating said diaphragm mechanism and opening saidfirst-mentioned valve on establishment of a negative pressure at saidoutlet side. means for moving said diaphragm mechanism in a reversedirection to close said valve when predetermined peak positive pressureis attained at said outlet side, and

means for differentially loading said diaphragm to control the peakpressure at said outlet side.

11. In a valve device for an oxygen feeding system of the characterdescribed, an outlet side thereof, a valve operable to control deliveryof side, a diaphragm mechanism responsive topressure at said outletside, mechanism responsive to operation of said diaphragm mechanism butpowered by oxygen pressure from said pressure source. for controllingthe movement of said first mentioned valve, means for actuating saiddiaphragm mechanism and opening said firstmentioned valve onestablishment of a negative pressure at said outlet side, means formoving said diaphragm mechanism in a reverse direction to close saidvalve when predetermined peak positive pressure is attained at saidoutlet side, and means for differentially loading said diaphragm tocontrol the peak pressure at said outlet side, and means for indicatingto a user the setting of said diiferential loading means and the peakpressure resulting therefrom.

12. In an oxygen flow regulator, a casing having a diaphragm with oneside thereof exposed to atmosphere, a low pressure chamber in the casinghaving one side thereof defined by said diaphragm, a high pressureoxygenchamber, a valve controlling flow from the high pressure to the lowpressure chamber, a toggle over center switch mechanism outside the lowpressure chamber and operably connected to said diaphragm, saidmechanism being biased to operate and open said control valve when aslight negative pressure is developed in said low pressure chamber, andto operate in an opposite direction when a peak positive pressure isdeveloped in said low pressure chamber, a diaphragm loading springoutside said low pressure chamber, said diaphragm loading spring beingnormally out of contact with the diaphragm, and means for moving saidloading spring a controlled distance toward the diaphragm to increasethe said peak pressure at which said toggle mechanism operates todiscontinue oxygen flow.

13. In an oxygen flow regulator, a casing having a diaphragm vwith oneside thereof exposed to atmosphere, a low pressure chamber in the casinghaving one side thereof defined by said diaphragm, a high pressureoxygen chamber, a

valve controlling flow from the high pressure to the low pressurechamber, a toggle over center switch mechanism outside the low pressurechamber and operably connected to said diaphragm, said mechanism beingbiased to operate and open said control valve when a slight negativepressure is developed in said low pressure chamber, and to operate in anopposite direction when a peak positive pressure is developed in saidlow pressure chamber, a diaphragm loading spring outside said lowpressure chamber. said 1 diaphragm loading spring being normally out, ofcontact with the diaphragm, and means for moving said loading spring acontrolled distance toward the diaphragm to increase the said peakpressure at which said toggle mechanism operates to discontinue oxygenflow, said moving means being. incapable of adding to the load of thediaphragm suificiently to operate the toggle mechanism when a positivepressure exists in said low,pressure chamber.

-14. In an oxygen flow regulator, a casing having a diaphragm with oneside thereof exposed to atmosphere, a low pressure chamber in the casinghaving one side thereof defined by said diaphragm, a high pressureoxygen chamber, a valve controlling flow from the high pressure to thelow pressure chamber, a toggle over center switch mechanism outside thelow pressure chamber and operably connected to said diaphragm, saidmechanism being biased to operate and open said control valve when aslight negative pressure is developed in said low pressure chamber, andto operate in an opposite direction when a peak positive pressure isdeveloped in said low pressure chamber, a diaphragm loading springoutside said low pressure chamber, said diaphragm loading spring beingnormally out of contact with the diaphragm, and means for moving saidloading spring a controlled distance toward the diaphragm to increasethe said peak pressure at which said toggle mechanism operates todiscontinue oxygen flow, said moving means being incapable of adding tothe load of the diaphragm sufliciently to operate the toggle mechanismwhen a positive pressure exists in said low pressure chamber, andadditional means 16 to load the diaphragm whereby to operate the togglemechanism and initiate oxygen flow when a slight positive pressure,below said peak pressure, exists in said low pressure chamber.

ALBERT E. McKEE. JAMES D. ELSOM.

REFERENCES CITED The-following references are of record in the file ofthis patent:

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